tests/ui/cross/cross-borrow-trait.rs

   1 // Test that cross-borrowing (implicitly converting from `Box<T>` to `&T`) is
   2 // forbidden when `T` is a trait.
   3
   4 struct Foo;
   5 trait Trait { fn foo(&self) {} }
   6 impl Trait for Foo {}
   7
   8 pub fn main() {
   9     let x: Box<dyn Trait> = Box::new(Foo);
  10     let _y: &dyn Trait = x; //~ ERROR E0308
  11                             //~| expected reference `&dyn Trait`
  12                             //~| found struct `Box<dyn Trait>`
  13 }